The Carbon Assimilation Network in Escherichia coli Is Densely Connected and Largely Sign-Determined by Directions of Metabolic Fluxes

Gene regulatory networks consist of direct interactions but also include indirect interactions mediated by metabolites and signaling molecules. We describe how these indirect interactions can be derived from a model of the underlying biochemical reaction network, using weak time-scale assumptions in combination with sensitivity criteria from metabolic control analysis. We apply this approach to a model of the carbon assimilation network in Escherichia coli. Our results show that the derived gene regulatory network is densely connected, contrary to what is usually assumed. Moreover, the network is largely sign-determined, meaning that the signs of the indirect interactions are fixed by the flux directions of biochemical reactions, independently of specific parameter values and rate laws. An inversion of the fluxes following a change in growth conditions may affect the signs of the indirect interactions though. This leads to a feedback structure that is at the same time robust to changes in the kinetic properties of enzymes and that has the flexibility to accommodate radical changes in the environment

Treatment of fatigue in multiple sclerosis: A systematic review of the literature.

NoFatigue is common in people with multiple sclerosis (MS) and symptoms of fatigue are often reported as the most debilitating symptoms of the disease. However, there are few reports of interventions for fatigue in MS. A systematic review of published literature examining pharmacological and psychosocial/psychological interventions for fatigue in MS was conducted. The search and review strategy undertaken used the Centre for Reviews and Dissemination guidelines. Papers were reviewed by two independent reviewers. Of 81 studies short-listed for inclusion, 15 studies were included, of which 10 were studies of pharmacological therapy and five were studies of psychosocial/psychological interventions. Of the pharmacological studies, two were rated as of moderate-to-high quality, three of moderate quality, two of moderate-to-low quality and three of low quality. Of the psychosocial/psychological studies, three were rated as of moderate quality and two of moderate-to-low quality. None of the studies reviewed reached the highest level of quality according to pre-agreed criteria. Regardless of level of quality, effectiveness of both pharmacological and psychosocial/psychological interventions was modest at best and often absent. Accordingly, there is little evidence-based advice that can be offered to people with MS to help manage their fatigue

The case for the virtual strike

In this paper we outline the economic rationale behind the virtual strike, and workers’ incentives to use this bargaining solution rather than resorting to standard strike action. We show that, from a welfare perspective, a well-designed virtual strike always dominates a standard strike and it would be most needed precisely when workers have weaker incentives to adopt it. We then discuss the pros and cons of legally regulating the virtual strike rather than leaving it to self-regulation. Finally, we apply our findings to the analysis of Italy’s draft legislation on virtual strikes

The case for the virtual strike

Stoppage strike, Virtual strike, Penal code, Labor law, D74, D78, J52, J83, K31, M55,